Agrippa

(1st/2nd cent. ad) Shadowy Roman sceptic. His legacy is the five ‘tropes’, partly a variation on the ten tropes of Aenesidemus, but adding a stress on the implicit infinite regress in every proof, arising because the premises have to be proved in turn, and further insisting that all attempts to halt the regress will involve either blatant circularity, or arbitrary dogmatism. The uncomfortable three options are known as Agrippa's trilemma.